Figure 1

Pedigrees and Sanger sequencing results in three families with CAPOS syndrome. A) Pedigees. Family 1 was initially described by Nicolaides et al. [1] Individuals with CAPOS syndrome are indicated by filled pedigree symbols, and unaffected individuals, by empty symbols. B) Sanger sequencing results in affected and unaffected family members. A portion of the Sanger sequencing trace is shown for each individual who was tested, with the nucleotides at Ch19:47,166,267, corresponding to ATP1A3 position c.2452 on the minus strand, indicated by a vertical blue line. Each affected individual is heterozygous for the variant T (corresponding to c.2452A) and the reference C (corresponding to c.2452G) nucleotides. C) Conservation of Na⁺/K⁺ ATPase α₃ protein sequence in the region of the mutation. The E818K mutation found in all three CAPOS families is shown in red type; the location of the E815K loss-of-function mutation, which is associated with alternating hemiplegia of childhood, is shown in blue type. This segment of the Na⁺/K⁺ ATPase α₃ protein is highly conserved.